What is Respiratory Syncytial Virus Prefusion F (RSVPreF3) Vaccine?
Vaccines for the respiratory syncytial virus (RSV) are recommended for adults over 60 years old and pregnant women between 32 to 36 weeks gestation. The RSV is a viral infection that affects the respiratory system and can infect people of all ages, although it is especially dangerous for infants, the elderly, and those with weakened immune systems. Common symptoms of RSV include a runny nose, cough, fever, and breathing difficulties. Serious cases can lead to pneumonia and respiratory failure.
RSV is highly contagious and spreads through droplets produced when an infected person coughs or sneezes. The virus can also live on surfaces, increasing the risk of infection when people touch these surfaces and then touch their face. RSV is equipped with a protein that enables it to enter host cells, causing infection.
In the United States, there are two approved vaccines for RSV which are designed to stimulate a strong immune response. One has an added element (adjuvant) which further boosts the immune system’s reaction. The vaccines were greenlit by the Food and Drug Administration (FDA) in May 2023 after comprehensive review confirmed their effectiveness and safety.
Later in August 2023, the FDA also approved one of the vaccines to be used in pregnant individuals from 32 to 36 weeks gestation. The idea is to protect infants in their early months after birth through the transfer of the mother’s vaccine-induced antibodies.
In clinical trials involving thousands of participants across several countries, the vaccines were proven to be significantly effective in preventing severe infections caused by RSV. Side-effects were minimal, usually mild-to-moderate, and temporary. Serious side-effects occurred at the same rate in both the group that received the vaccine and the group that received a placebo (non-active substance). Further extensive tests in non-pregnant and pregnant women showed the same promising results. The vaccine was particularly effective in preventing severe RSV infections in infants within the first 90 days after birth.
What Causes Respiratory Syncytial Virus Prefusion F (RSVPreF3) Vaccine?
The RSVPreF3 and RSVPreF vaccines protect against the Respiratory Syncytial Virus (RSV) by targeting specific proteins on the virus’s surface. These proteins are crucial for the virus to enter human cells. The vaccines stimulate the immune system to produce antibodies that can recognize and attach to these proteins, preventing the virus from infecting cells and reducing the chance of infection and virus growth. The vaccines also enable pregnant women to pass protective antibodies to their babies, providing them with some protection against RSV in the early months of life. In addition to antibody production, the vaccines also stimulate CD4 T cells and memory B cells, which contribute to immunity and help the body respond quickly and strongly to future exposure to RSV. The RSVPreF3 vaccine contains an adjuvant called AS01, which enhances the immune response to the vaccine and helps counterbalance the natural decrease in immunity that occurs with aging.
Risk Factors and Frequency for Respiratory Syncytial Virus Prefusion F (RSVPreF3) Vaccine
Vaccines and the fluids used to mix them, known as diluents, should be kept in the fridge between 2 and 8°C (36-46°F), and be shielded from light in their original packages. Once a vaccine is mixed, it should be used right away. If it can’t be administered immediately, it needs to be kept away from light and either stored in the fridge or at room temperature. Any mixed vaccine not used within four hours should be thrown away.
The two vaccines, RSVPreF3 and RSVPreF, are prepared by mixing them with specific fluids. RSVPreF3 is mixed with the adjuvant solution, while RSVPreF is mixed with sterile water. Only the fluid provided by the vaccine manufacturer should be used for this.
The vaccines are given as an injection into a muscle. Each dose contains 120 μg of vaccine. The RSVPreF3 also contains 25 μg each of QS-21 and MPL.
For adults, a single dose of 0.5 mL is recommended after the vaccine has been mixed. People can also get the RSVPreF3 or RSVPreF with any other adult vaccine during the same appointment.
For adults aged 60 or older, either the RSVPreF3 or the unadjuvanted RSVPreF may be a good option. During a discussion with a healthcare provider, factors such as the likelihood of severe RSV-LRTD, personal preferences and values, and the clinician’s decision will be considered. Risks for severe RSV-LRTD include:
- Chronic obstructive pulmonary disease
- Moderate or severe immunocompromise
- Congestive heart failure
- Stroke
- Blood disorders
- Chronic kidney disease
- Medical frailty
- Living in a long-term care facility
Pregnant people can only get the RSVPreF vaccine. It is recommended to be given once at 32-36 weeks of pregnancy, from September to January, during RSV season. Vaccine timing can vary depending on local climate, so check with local health guidance for the best timing. The CDC doesn’t currently say if additional doses should be given during later pregnancies, but may update this as more data becomes available.
Nirsevimab, a long-acting antibody against RSV, can be given to young babies and high-risk infants and toddlers. The CDC suggests either vaccination during pregnancy or Nirsevimab for babies less than 8 months, but not both. Doctors should discuss the benefits and risks of both the vaccine and Nirsevimab with pregnant people. Even if the parent received the vaccine during pregnancy, high-risk older babies and toddlers can still receive Nirsevimab in their second RSV season.
Testing for Respiratory Syncytial Virus Prefusion F (RSVPreF3) Vaccine
The RSVPreF3 and RSVPreF vaccines are new strategies to help protect older adults and infants from the health risks of RSV. It’s important for all healthcare professionals to work together and communicate effectively for the vaccines to be administered safely and efficiently.
Healthcare workers from a variety of fields such as doctors, nurses, pharmacists, and other medical staff, should have complete education and training about these vaccines. This includes understanding when the vaccines should be used, when they shouldn’t be, how much to give, how to administer it, and potential side effects. Staff should be kept up-to-date with the latest guidelines and recommendations about these vaccines. Even non-medical staff should be educated about the vaccines to ensure they give patients correct information.
A team approach is also needed when deciding whether a patient should get the RSVPreF3 and RSVPreF vaccines. This means healthcare professionals should talk with patients and their caregivers about the pros and cons, and possible outcomes of the vaccination. This helps address any questions or worries, and ensures that patients and caregivers are part of the decision-making process.
All healthcare team members should follow standard procedures when giving the vaccines. This includes knowing the right way to store, prepare, handle, and give the vaccines. Clear lines of communication should be in place to ensure that everyone involved in giving the vaccine operates in a consistent manner, following the procedures.
It’s also important for all healthcare professionals to monitor and report any side effects from the vaccines. Everyone should understand how to report side effects and make sure to do so quickly to the right authorities. Sharing this important information helps keep track of vaccine safety after it has been released on the market.
